1. Field of the Invention
The present invention provides photosensitive image forming materials obtainable at low cost which have various excellent properties such as high light-blocking property, high resolving power and stability with the passage of time, whereby image forming processing is shortened. Particularly, the invention relates to photosensitive image forming materials capable of providing black images without a metallic luster.
2. Description of the Prior Art
An image forming process involving using a photosensitive image forming material comprising a photosensitive resin composition layer on a base and various thin metal layers between the base and the photosensitive resin composition layer which comprises imagewise exposing the photosensitive resin composition layer to light, developing and thereafter etching the thin metal layers is known.
Further, an image forming process using a photosensitive image forming material comprising a photosensitive resin composition layer on a base and a thin metal layer (such as aluminum or tellurium) between the base and the photosensitive resin composition layer which comprises imagewise exposing to light, and developing and etching in one bath using an aqueous alkaline solution to shorten processing is described in Japanese patent application (OPI) Nos. 65927/73 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application"), 65928/73, 139720/75 (U.S. Pat. No. 4,008,084), 131625/76 (British Pat. No. 1,514,420), 99811/77, 99814/77, 99102/77, 109926/77 (British Pat. Nos. 1,546,739) and 99810/77 (U.S. Pat. No. 4,139,391).
These prior art processes yield excellent images having high light-blocking property, high resolving power and good edge sharpness, but have the faults that the images produced do not have strong black coloration, rather have a metallic luster similar to a mirror surface and are difficult to view as compared to silver images formed from silver halide sensitive materials. Paticularly in the case that a half tone image is formed and used as a mask in the graphic art field the fault is encountered that the degree of gradation is difficult to estimate. On the other hand, blackening of the image forming layer yields the effect that the resulting black layer acts as an antihalation layer in the case of imagewise exposing the photosensitive resin composition layer to light to further improve resolving power.